Freezing cells- Media or FBS ?

Hi, I'm attempting to freeze HT29 cells for the first time. I looked up various protocols online. Some (such as the one posted on the forum by minne mouse) use cell culture medium + 10% (v/v) DMSO. While others use FBS + 10% DMSO. Which one should I be using ? Is there a difference ?

We always freeze our cells in 70% growth medium (including FBS), 20% FBS and 10% DMSO. Works well for us. I never count the cells but I write the splitting factor (e.g. 1:10 from T25 flask) on the tube.

wow another method... had no idea there was so much variability in just the composition of the freezing media. I'm dealing with HT29 (cancer cells) and RINm5F cells (insulin secreting beta cells). Any suggestions for the best freezing media ?